Search NASA⌕ Search

Engineering topics

Graves, Russell

Publications and source records attributed to Graves, Russell.

Preliminary Assessment of Potential Habitat Composites' Durability when Exposed to a Long-Term Radiation Environment and Micrometeoroid Impacts

NASA's exploration goals include extending human presence beyond low earth orbit (LEO). As a result, habitation for crew is a critical requirement for meeting this goal. However, habitats are very large structures that contain a multitude of subsystems to sustain human life over long-durations in space, and one of the key challenges has been keeping weight to a minimum in order to reduce costs. Thus, light-weight and multifunctional structural materials are of great interest for habitation. NASA has started studying polymeric composite materials as potential lightweight and multifunctional structural materials for use in long-duration spaceflight. However, little is known about the survivability of these materials when exposed to the space environment outside of LEO for long durations. Thus, a study has been undertaken to investigate the durability of composite materials when exposed to long-duration radiation. Furthermore, as an addition to the primary study, a secondary preliminary investigation has been started on the micrometeoroid and orbital debris (MMOD) susceptibility of these materials after radiation exposure. The combined effects of radiation and MMOD impacts are the focus of this paper.

Rojdev, Kristina↗

Code Assesses Risks Posed by Meteoroids and Orbital Debris

BUMPER II version 1.92e is a computer code for assessing the risk of damage from impacts of micrometeoroids and orbital debris on the International Space Station (ISS), including those parts of the ISS covered by shielding that affords partial protection against such impacts. (Other versions of BUMPER II have been written for other spacecraft.) Bumper II quantifies the probability of penetration of shielding and the damage to spacecraft equipment as functions of the size, shape, and orientation of the spacecraft; the parameters of its orbit; failure criteria that quantify impact damage at the threshold of failure for each spacecraft surface; and the impact-damage resistance of each spacecraft surface as defined by "ballistic limit equations" that return the size of a failure-causing particle as a function of target parameters (including materials, configurations, thicknesses, and gap distances) and impact conditions (impact velocity and the density and shape of the impactor). BUMPER II version 1.92e contains several dozen ballistic limit equations that are based on results from thousands of hypervelocity impact tests conducted by NASA on ISS shielding and other hardware, and on results from numerical simulations of impacts.

Christiansen, Eric L.↗

International Space Station: Meteoroid/Orbital Debris Survivability and Vulnerability

This slide presentation reviews the surviability and vulnerability of the International Space Station (ISS) from the threat posed by meteoroid and orbital debris. The topics include: (1) Space station natural and induced environments (2) Meteoroid and orbital debris threat definition (3) Requirement definition (4) Assessment methods (5) Shield development and (6) Component vulnerability

Graves, Russell↗